Coated textile materials and process



Jan. 26, 1965 P. J. DE NIJS 3,167,446

COATED TEXTILE MATERIALS AND PROCESS Filed Feb. 20, 1962 TREATMENT OF NAPPED COTTON FABRIC WITH POLYAMIDE SOLUTION CONTAINING DISPERSED SULPH ITED UNSATURATED OIL REMOVAL OFEXCESS SOLUTION COAGU LATI ON OF POLYAM I DE WASHING TREATMENT WITH ALKALINE SOLUTION AND/OR WASHING DRYING INVENTOR Petrus Johannes de Nijs ATTORNEYS 3,167,446 Patented Jan. 26, 1S65 fiice 3,167,446 COATED TEXTILE MATELS AND PROCESS Petrus Johannes de Nijs, Kaatsheuvei, Netherlands, as-

signor to N.V. Lederfabriek L. Mombers, Waalwijk, Netherlands, a corporation of the Netherlands Filed Feb. 20, 1962, Ser. No. 174,407 Claims priority, application Netherlands, Mar. 3, 1961,

Claims. (Cl. 11742) This invention relates to a proces for the manufacture of a textile material coated with a polyamide, and to the textile products thus manufactured.

Processes of this general character employing cotton fabrics are of course broadly old. For example by a known process fabrics are obtained which are whiter and less transparent than the starting fabrics and which are very supple. This suppleness is not obtainedin the case of fabrics which. are merely treated with a solution of a polyamide in a volatile solvent, after which the solvent is evaporated.

It has been discovered according to the present invention that coated textile products may be obtained which, in contrast to the products of the above-mentioned broadly old process, compare to a certain extent with natural wash-leather or chamois.

According to the present invention, as illustrated by the fiow sheet of the process in the drawing, a napped cotton fabric is treated with a polyamide solution containing a dispersed, sulphited unsaturated oil in an amount which is larger than that of the polyamide contained in the solution,-the oil being at least partly removed bywashing after .the coagulation of the polyamide.

The weight per square meter of the cotton fabric should preferably be from 150 to 300 grams, and still more preferably from 175 to 225 grams. At such a weight the treated cotton fabric has the most favorable washing capacity. The cotton fabric should preferably be napped on both sides and during manufacture be subjected to a high degree of contraction or shrinkage.

Napping the fabric on both sides serves to insure that after the impregnation with the polyamide solution and the coagulation thereof, the precipitated polyamide will be firmly anchored substantially in the projecting cotton fibers. A high degree of contraction of the starting cotton fabric favorably influences the anchorage in the projecting cotton fibres.

The structure of the resulting textile product insures that the appearance and the-handlev thereof will .co'r'respond to a great extent to those of naturalwash-leather.

Another essential condition for obtaining a product resembling wash-leather, in accordance withthe present invention, is thata sulphited unsaturated oil is worked up in the polyamide solution.

By a sulphited unsaturated oil is to be understood an unsaturated oil or fat which is treated with sulphur dioxide in an amount such that the treated oil or fat is dispersible in strong formic acid. An example of such a sulphited oil is a sulphited fish-oil. 1 p

A specific example thereof is Prinol T.G., marketed by Messrs. Schimmer & Schwarz. I

Such a sulphited oil may be obtained by treating unsaturated oils or fats, in a per se known manner, at tem-, peratures above 60 C. and, if desired, in'the presence of suitable catalysts such as lead naphthenate, cobalt soaps, manganese soaps, or zinc soaps, with oxidants and sul phites, for instance,- sodium bisulphite, until thedisp'ersibility of the resulting oilsin water no; longer increases It appears that proceeding in this way the oils are'only partly sulphited.

with sulphites at temperatures between 70 and 110 C.

Products which are also suitable are, for instance, sulphited sperm oil, sulphited coconut oil, sulphited linseed oil, and other sulphited oils having an iodine number higherthan 100, in particular an iodine number of about 160.

The sulphited oils must be added to the polyamide solution in an amount which is at least equal to that of the polyamide in the solution.

As far as moisture absorption capacity and washing power are concerned, the most favorable results are obtained if use is made of a polyamide solution containing an amount of sulphited oil which is twice that of the polyamide in the solution.

Generally, however, the sulphited oil is not used in an amount more than three times the amount of polyamide in the solution, since as a rule such an amount may give rise to ditficulties in the preparation of the solution.

It appears that the action of the sulphited oil is twofold. The polyamide precipitate is somewhat porous and, moreover, after washing,-the product is still oilqetaining. Both facts are considered as contributing to the satisfactory water-absorption capacity of the final textile product. The amount of polyamide which is precipitated on the textile product may vary between fairly wide limits.

In order to obtain a supple textile product, it is preferred to treat the fabric with such an amount of the polyamide solution that the resulting synthetic wash-leather contains at the most 35% by weight, and preferably about 30% by weight of polyamide; As lower limit a value of 20% by weight, calculated on the synthetic leather product, may be taken as satisfactory.

As polyamides there may be used those based on diamines and dicarboxylic acids, or polyaminocarboxylic acids such as poly-e-aminocaproic acid. The latter type of polyamides, however, yield the best synthetic washleathers. v

Generally speaking, since the polyamides per se are well known and form no part of the present invention it is deemed unnecessary in the interests of brevity to do more than refer in passing to typical prior art disclosures illustrative thereof merely by way of example, such as Du Ponts numerous U.S. patents to Carothers including Nos. 2,07l,250-3 and 2,130,948 and the Collected Papers of Wallace Hume Carothers on High Polymeric Substances, Interscience Publishers, Inc., New York, 1940. Another useful definition of these polyamides (patterned after Wakeman, The Chemistry of Synthetic Plastics, Reinhold Publishing Corp, 1947-, page 257) is that they are long-chain synthetic. polymeric carbonamides which have I recrurring'carbonamide groups as an integral part of the main polymer chain.

It should be mentionedin passing that the amount of polyamide to be used is to some extent dependent, on the one hand, on the weight of the fabric, and on the other hand, upon the length of the projecting fibers and the degree of napping, that is the number of projecting fibers per unit surface area of the fabric. 1 j In the case of alarge number of long projecting fibers per unit surface area of the fabric, the amount of polyamide applied will be relatively high, whereas relatively low percentagesby weight will normally'be used in the case of fabrics having relatively few and/or shortfibers per unit surface area.

Moreover, relatively small amounts of polyamide will be used for fabrics having'relatively high weights per square meter.

" In this connection, however, it has been found'to be I of some importance that" the freeends of the projecting Unsaturated oils may also be sulphited by treating them" fibers shall be hardly, or not at all, covered by the polyamide.

In order to obtain a good distribution of the polyamide on the cotton fabric, it is preferred to use a polyamide solution, although the use of solutions -having dif-' ferent concentrations is within the contemplation of the invention.

If, however, the percentage of polyamide in the solu-f tion is lower than 5%by weight, then the desired amount of polyamide 'doesnot so readily precipitate on the fabric.

In the case of percentages by weight higher than the high viscosity of the solution appears to be a drawback. Moreover, in the latter case the coagulation of the polyamide requires too much time.

Finally, in order to increase the washing action, orcase with which they may be washed, of the textile prod-.

ucts manufactured according'to the present invention, it has been found particularly favorable to subject the textile products to a grinding or abrading treatment after treating them with the polyamide solution but before drying.

The grinding treatment is preferably carried out by continuously passing a length of the polyamide-coated fabric over a grinding roller which is driven in thedirec- The textile product may be dyed prior to drying, or a suitable dye-stuff maybe added to the polyamide solution itself. 1

Moreover, the drying step may be preceded by treat- I ing the ground and washed textile product with an alkaline solution, for instance a solution of sodium hydroxide, soda, sodium bicarbonate or ammonia. Such a treatment furthers the de-swelling of the coagulate. In

general, these alkaline reagents are preferably used in solutions of from 1 to 5 %,by Weight.

As, far as washing power is' concerned, the textile products manufactured according to the present invention compare favorably with those products which are manufactured'by treating fiber webs, in one or rnore amounts which are at least equal to the amounts of polyamides in these solutions.

The present invention also relates to the textile products obtained by the methods described herein. The

' treated products are characterized by a'napped cotton fabric having a weight of, preferably, 150 t oJ300 grams per squaremeter, which fabric isprovided on at least one side with a discontinuous, porous layer 'of a polyamide.

7 As a rule, these products contain at least 2.5% by weight of a sulphited oil, and 20-35% by weight of polyarnide After impregnation of the fabric, the excess of imprege nation solution was removed by passing the fabric be tween two knife edges positioned at some distance from each other, as a result of which the textile product was also smoothed out. Subsequently, the fabric was passed into Water at 10 C., .as a result of which thelpolyarni de solutionwas coagulated thereon. The scraping device.

was so adjustedthat-in the dried statethe coate'dltextile product had increased in weight by about 80 grams per square meter. After coagulation, I116 coated textile product was washed with water at about 10 C. and subsequently passed over a grinding roller which was rotated in the direction of travel of theicoated product and which was, moreover, caused to traverse in an axialdir'ection. The grinding roller Was clad with water-resistant Garborundurn paper having afinenessof 400. a

After grinding, the coated, product was treated with a 4% by weight solution of sodium carbonate, at 60 to 80 C., rinsed with water at, 10 C. to wash out the soda;

, subsequently treated with water containing 1% by-weight 'tion of travel of the fabric and, moreover, is simulta- Alsoduring grinding, Water may be sprayed against the fabric.

present invention is lowerthan that ofa natural wash In order-to indicate still more fully the nature of the presentinvention, the following example of; typical pro-' cedures is set forth, it being understood, however, that this description is presented by Way of illu'stration only,

and'not as limiting thescope of the invention.

. Example Y A'cottonfabric (flannel) having a weight of 19.7 grams in a continuous process with aisolution of 10% by weight of'polyaminocaproic acid in by weight formic acid containing 'dispersed sulphited 'fish-oil'in-an amount twice that of the polyamidef-"This' s'ulphitedQfish-oilwas,the; Y I product marketed by Messrsi 'Schimmer & Schwarz under thetrade'namePrin'olTfifif r T I the alkaline solution and the treatment vw'th 'Water,:-for

the purpose of speeding up the washing treatment. The

of the sulphited oil.

. dried wash-leather still contains more than 3% by We Although the'water-absorption capacity of the no thetic wash-leather manufactured in accordance with the leather or chamois, the coated textileproduct made ac cording to this invention feels like a natural wash-leather, and behaves as such as far as the quality is concerned, and is remarkable for its higher resistance to boiling water, synthetic detergents, decay, and adverse inechani= cal influences such as abrasion. Moreover, the product of the present invention will not become slimy in use. Moreover, and in contrast with natural wash-leathers, it will also readily absorb moisture when in the air-dry state.

While a specific example of a preferred rnethod and product embodying the present invention has been set forth above, it will be'unde'rstood that many changes. and modifications may be made in the methods of procedure and in the resulting products without departing from the spirit of the invention. It will thereforebe understood that the example cited and theparticular proportions and methods of operation and resulting products set forth above are intended. to be illustrative only, and are notintended to limitthe scope of .the invention.

What is claimed is:

1. In a process for themanufacture of a tcxti-lema A terial coated witha polyamide in which a cotton fa bric is treated with a solution of a polyamide in formic acid and the polyarnide is precipitatedfrom the solution onto the fabric with the aid of an aqueous liquid, after which the sulphited oil being at least partially removed bywashing, after the coagulation of the polyamide. I f I I 2. A process as definedin claim 1, wherein the cotton fabric, has meter.

-3. A' process as definedinclaim 1, wherein thetsul phited unsaturated oil isasulphited fish -oil." 4. A process as defined in claim 1,- wherein the-polyamide solution contains an amountfof-sulphited unsatu- ,rated oil which is twice that of the polyamide'in the; .solution. Y

5; A'process as defined in claim 1, wherein the cotton.

fabric is treatedlwith such an amount of the .polyamideu a weight of to 300 grams persquaresolution that the treated fabric product contains from 20 to 35% by Weight of polyamide.

6. A process as defined in claim 1, wherein the cotton fabric is treated with such an amount of the polyamide solution that the treated fabric product contains about 30% by weight of polyamide.

7. A process as defined in claim 1, wherein a solution of 10% by Weight of polyaminocaproic acid in an aqueous solution of 85% by Weight formic acid is employed as the polyamide solution.

8. A process as defined in claim 1, wherein the textile material is treated With an alkaline liquid before drying.

9. A textile product comprising a napped cotton fabric having a weight of 150 to 300 grams per square meter, and being provided on at least one side thereof with a discontinuous, porous layer of a polyamide and a sulphited, unsaturated oil, said polyamide constituting from 20% to 35% by Weight of said textile product and said oil constituting at least 2.5% by Weight of said textile product.

10. A textile product as defined in claim 9, wherein the polyamide content is about 30% by weight.

References Cited by the Examiner UNITED STATES PATENTS 1,406,710 2/22 Wilson 117-11 X 1,472,230 10/23 Plum 117-11 X 1,955,766 4/34 Pohl 117-139.5 2,025,989 12/35 Kaplan 117-139.5 2,334,107 11/43 Light et al. 117-1395 2,345,632 4/44 Robinson et a1 117-139.5 2,714,075 7/55 Watson et al. 117139.5 2,820,724 1/58 Sneed 117-139.5 2,871,145 1/59 Hajdu 117-1395 2,882,185 4/59 Valko et a1. 117139.5 2,933,409 4/60 Binkley et a1. 117-11 3,067,482 12/62 Hollowell 117-63 X 3,100,721 8/63 Holden 117-73 FOREIGN PATENTS 458,881 8/49 Canada.

WILLIAM D. MARTIN, Primary Examiner.

MURRAY KATZ, RICHARD D. NEVIUS, Examiners. 

1. IN A PROCESS FOR THE MANUFACTURE OF A TEXTILE MATERIAL COATED WITH A POLYAMIDE IN WHICH A COTTON FABRIC IS TREATED WITH A SOLUTION OF A POLYAMIDE IN FORMIC ACID AND THE POLYAMIDE IS PRECIPITATED FROM THE SOLUTION ON TO THE FABRIC WITH THE AID OF AN AQUEOUS LIQUID, AFTER WHICH THE TEXTILE PRODUCT IS WASHED; THE IMPROVEMENT CHARACTERIZED IN THAT A NAPPED COTTON FABRIC IS TREATED WITH A SOLUTION OF FROM 5% TO 20% BY WEIGHT OF POLYAMIDE CONTAINING A DISPERSED, SULPHITED UNSATURATED OIL IN AN AMOUNT WHICH 